time given in seconds

[maikia]

The time for the running submissions is given in seconds. However, if this time is very large it becomes not very informative, eg

It would be better to have something of type h : m : s in the display

[agramfort]

+1000

…

[kegl]

+1. Last year in #276 I rounded it to second, but @rth had a remark that for very short jobs we should not have an integer 0. So some more sophisticated rounding would be perhaps better. In money-prize challenges we usually give them a max total time given in minutes, so the rounding should not be smaller than minutes, but we could get rid of the seconds if it's more than, say, 1h.